Currently, organic light emitting diode (OLED) panels are being introduced into next generation displays. An OLED panel includes a plurality of pixels. FIG. 1 shows each of the pixels in an OLED panel including a red sub-pixel, a green sub-pixel and a blue sub-pixel. Generally, an organic emitting material corresponding to an emitting color is injected into a containing area of the OLED panel. The emitting efficiency of the organic emitting materials corresponding to different emitting colors is different. For the purpose of keeping the same emitting intensity of the red sub-pixel, the green sub-pixel and the blue sub-pixel, the corresponding emitting area of the red sub-pixel, the green sub-pixel and the blue sub-pixel is inversely proportional to the emitting efficiency of the corresponding organic emitting materials. The emitting efficiency of the red emitting material is the highest such that the emitting area of the red sub-pixel is the smallest. The emitting efficiency of the blue emitting material is the lowest such that the emitting area of the blue sub-pixel is the largest.
The emitting area of the sub-pixel becomes smaller when the PPI (pixels per inch) of the OLED panel becomes higher. However, if the emitting area of the sub-pixel is smaller than the diameter of the droplet of the corresponding emitting material, the droplet of the corresponding emitting material cannot totally inject into the containing area corresponding to the sub-pixel. It causes the droplet to be deposited outside the containing area, and the color mixing issue. Therefore, the resolution of the current OLED panel is limited.